How is it not the same? Some employees of Red Hat can have the power to decide or directly influence if a change becomes part of the linux kernel. Some employees of the DoD can have the power to decide or directly influence if a becomes part of TOR. It is exactly the same; the people who have the most expertise regarding something specific generally are those who have the power to decide the changes and influence it. And when it comes to Open Source Projects, those people generally work for companies that can use their expertise with regards to the open source project, or their company made the project to begin with.
In the case of some of the Bitcoin Core devs and Blockstream, some of the Core devs have the expertise of working with Bitcoin, and thus they founded or were hired by Blockstream.
It will be obvious if instead of blindly defending you try and understand with an open mind. In your example both will be same if RED HAT GETS A FINANCIAL BENEFIT FROM IMPLEMENTING A FEATURE INTO LINUX KERNEL AND THEY HAVE THE POWER TO DECIDE/INFLUENCE IT, which is true with blockstream which has direct financial incentive to make segwit/lignting network part of bitcoin.
I would suggest you should read some real world examples of "Confict of Interest" so that you can understand, otherwise no matter what I say, it will not make any difference to you , if you have already made your decision.
Also this is not about segwit/lightning, if it is good thing or bad, even if segwit/lightning is perfect solution as you seem to think, the actions of the core developers are completely unethical and wrong.
It was not just those who work for Blockstream who implemented Segwit and lightning and decided that it should go into Core. It was implemented and modified by multiple people, proposed by multiple people, and reviewed by multiple people, many of whom are not affiliated with Blockstream in any way whatsoever.
If you say it is about making an income , so the developers need to be affiliated with Blockstream, I don't agree. No one can deny that bitcoin core developers are one of the top programmers in the world and they can very easily get a job at any of the top companies and make a good income, but choosing Blockstream and then promoting segwit/lightning is just being greedy and dishonest. They are abusing their position and trust that the bitcoin community has in them.